For service and parts needs, visit your dealer. You will receive genuine GM parts and GM-trained and supported service people.
Genuine GM parts have one of these marks:

Vehicle Care
California Proposition 65 WarningCustomer Satisfaction Procedure
Your satisfaction and goodwill are important to your dealer and to Chevrolet.
Normally, any concerns with the sales transaction or the operation of the vehicle
will be resolved by your dealer's sales or service departments. Sometimes, however,
despite the best intentions of all concerned, ...
Tracing Powder or Chalk Test
Clean the weatherstrips and the contact surfaces with cleaning solvent.
Apply powder or chalk in an unbroken line to the contact surface of the
weatherstrip surrounding the perimeter of the suspected
areas.
Close the panel completely without slamming the panel. Closing the panel
comple ...
Rear Side Door Adjustment
Rear Side Door
Caution: Refer to Fastener Caution in the Preface section.
Procedure
Loosen the rear door hinge bolt (Qty: 4) to adjust the rear door.
Adjust the rear door in order to obtain an even gap between the rear
door and the roof, the quarter outer panel, the
rocker pan ...